Zoysia grass plant `Z-3`

ABSTRACT

I disclose that my herein invention of a new variety of Zoysia grass plant was discovered by me as a found seedling in a pot of sterile medium on my farm in Waimanalo, Oahu, Hawaii. This new discovered Zoysia grass plant is a perennial, which exhibits an attractive deep green color, color Green number 141 A, as defined by The Royal Horticultural Society of London Colour Chart, of a low decumbent dense growth habit, that produces outstanding vigorous growth and a prolific rhizome system. The anthers are dark purplish-red color, color Red-Purple 61 B; the stigmas are pale yellow-green, color Yellow-Green 150 D. The entire plant of the new claimed variety of Zoysia grass plant, is glabrous except for several short hairs at the top of the leaf sheath at the sides of the ligule.

BACKGROUND AND SUMMARY OF THE INVENTION

The present invention relates to a new and distinct variety of Zoysiagrass plant which was disovered by me, growing as a newly found seedlingin a tray of sterile, inert, volcanic cinder on my farm in Waimanalo,Oahu, Hawaii. About fifty trays filled with undecomposed, insert,sterile volcanic cinder had been set in the field on plastic sheetsbetween mature flowering stands of `El Toro` Zoysia grass (Zoysiajaponica) and Hawaiian `Emerald` Zoysia grass (Zoysia matrella type). Itshould be noted that what is commonly referred to as `Emerald` Zoysiagrass in Hawaii is distinctly different from `Emerald` Zoysia grass(Zoysia japonica×Zoysia tenuifolia) imported from U.S. Department ofAgriculture, Beltsville, Md. and more closely resembles, but is notidentical to, Zoysia matrella imported from Auburn University, Auburn,Ala.; therefore, I have categorized Hawaiian `Emerald` Zoysia as aZoysia matrella type. The cinder-filled trays, used to germinate variouspalm seeds, were observed by me to have a number of Zoysia grassseedlings growing in them. Since the trays were surrounded by mature,flowering stands of `El Toro` Zoysia grass and Hawaiian `Emerald` Zoysiagrass, it was assumed that the origin of the seedlings was from thesurrounding Zoysia grasses. Over a period of approximately 3 months,several hundred Zoysia grass seedlings were observed for desireablegrowth characteristics and removed from the cinder-filled trays. Mostwere immediately discarded because of undesireable characteristics suchas poor vigor or color, but several dozen selections were retained andplanted in sterile medium in trays. Following continued observation fordesireable growth characteristics, all but 20 of the selections werediscarded; the 20 remaining selections were increased by me by dividingsufficient stolon and rhizome material of each selection to furtherreplant each of the 20 selections into ten 10" by 20" flats. Followingobservation for desireable characteristics, one selection, designated`Z-3`, showed superior and unique growth characteristics as follows:exceptional vigor, low decumbent growth habit, lusterous attractive leafcolor, leaf blades softer to the touch than `El Toro` Zoysia grass orHawaiian `Emerald` Zoysia grass, leaf size intermediate between `ElToro` Zoysia grass and Hawaiian `Emerald` Zoysia grass, and a verydense, tight growth habit without excessive formation of thatch. In1988, the ten flats of `Z-3` stolon and rhizome material were divided byme and planted out into the soil in an area of 15' by 30', andfertilized and mowed regularly to form a turfgrass surface, forobservation of growth habit, flowering characterics, and phenotypicstability. In early summer 1992, stolons and rhizomes were extractedfrom this plot by me and planted both in a composted wood shavings/horsemanure medium on plastic on beds totalling 5,000 ft2, and in the soiltogether with `El Toro` Zoysia grass and Hawaiian `Emerald` Zoysia grassin three adjacent 12' by 12' plots for comparative observation. Allplantings were at our farm in Waimanalo, Oahu, Hawaii. Under identicalgrowing conditions and planting rates, the following phenotypicdifferences were measured: Z-3 Zoysia grass: culms 5-6.5 centimeters;first mature leaf 2-3 millimeters in width, 5- 7 centimeters long;stolons a dark purplish-red color, color Red-Purple, number 61 B of TheRoyal Horticultural Society of London Colour Chart, 1.5 millimeters inwidth with nodes 1.2-2 centimeters apart, versus `El Toro` Zoysia grass:culms 10-15 centimeters; first mature leaf 3-4 millimeters in width,15-20 centimeters long; stolons a dark purplish-red color, colorRed-Purple, number 59 A of The Royal Horticultural Society of LondonColour Chart, 2 millimeters in width with nodes 1.5-2 centimeters apart,versus Hawaiian `Emerald` Zoysia grass: culms 3-5.5 centimeters; firstmature leaf 1.3-1.7 millimeters in width, 4-6 centimeters long; stolonsa dark purplish-red color, color Red-Purple number 59 B of The RoyalHorticultural Society of London Color Chart. In addition, it was notedthat, under identical growing conditions and planting rates, Z-3 Zoysiagrass covered the ground in approximately 3 months, faster than Hawaiian`Emerald` Zoysia grass, and slightly slower than `El Toro` Zoysia grass;the resultant sod grew as densely as Hawaiian `Emerald` Zoysia grass,and more densely than `El Toro` Zoysia grass; the leaves were softer tothe touch than either Hawaiian `Emerald` Zoysia grass or `El Toro`Zoysia grass; the root density of Z-3 Zoysia grass was greater than thatof Hawaiian `Emerald` Zoysia grass, and approximately equal to that of`El Toro` Zoysia grass; Z-3 Zoysia grass had 189 rhizomes per squaredecimeter versus 112 rhizomes for `El Toro` Zoysia grass and 171rhizomes for Hawaiian `Emerald` Zoysia grass; thatch formation of Z-3Zoysia grass was much less than that of Hawaiian `Emerald` Zoysia grass,and somewhat more than that of `El Toro` Zoysia grass; seedheads of Z-3Zoysia grass were much less conspicuous than those of either Hawaiian`Emerald` Zoysia grass or `El Toro` Zoysia grass; maximum height ofunmowed Z-3 Zoysia grass was 15-20 centimeters, the same as Hawaiian`Emerald` Zoysia grass and less than the 30-40 centimeter height of `ElToro` Zoysia grass. Although the parentage of Z-3 Zoysia grass isuncertain, because of its many intermediate phenotypic characteristicsand the position of the original found seedling between mature floweringstands of `El Toro` Zoysia grass and Hawaiian `Emeral` Zoysia grass, itmay be assumed to be a hybrid between these two. Since it more closelyresembles `El Toro` Zoysia grass than Hawaiian `Emerald` Zoysia grass,it could also be a self-pollinated offspring of `El Toro` Zoysia grass,or it could have come from another, unknown source.

Flowers of Z-3 Zoysia grass have produced seeds, whose viability is asyet untested. A plot of unmowed Z-3 Zoysia grass survived and maintainedits original color without any irrigation or fertilizer during a 6 monthwarm dry summer season period, suggesting its potential for low waterand fertilizer imputs. In Manatee County, Fla., Z-3 Zoysia grass plantednext to `El Toro``Meyer`, and `Emerald` Zoysia grass showed no damagefrom hunting billbugs during the 1992 summer season, whereas the otherZoysia grasses showed severe to moderate damage; and Z-3 Zoysia grasssubmerged in flood water for 2 days showed no color loss, whereas`Meyer` and `Emerald` Zoysia grass showed color loss. Z-3 Zoysia grassis well-adapted to semi-tropical Hawaii, but its cold-hardiness is asyet untested. The novelty and potential advantages of Z-3 Zoysia grasswhen compared to the closest known varieties of Zoysia grasses, `ElToro` Zoysia grass and Hawaiian`Emerald` Zoysia grass are as follows:its very dense, tight, decumbent growth habit, with the resultantpotential to block out emerging weeds; its proliferation of rhizomes,with the potential for superior recovery from damage or sod-harvesting;its very inconspicious seedheads, low growth habit, and minimal thatchaccumulation, with the potential for less frequent mowing or use as anunmowed ground cover; its softer leaf blades, with the potential formore comfortable home lawn activities; and its deep green lusterousintermediate-textured leaves, with the potential for a more pleasingaesthetic appearance. Continued asexual propagation by me throughstolons and rhizomes of this new variety of Zoysia grass plant, hasconfirmed that clones of the claimed plant have been found to retain allof the distinguishing characteristics of the originally discoveredseedling, and the plant thereby has been established to be stable.

A primary object of the invention is to provide a new and distinctvariety of Zoysia grass having the desireable characteristics referredto above and described in detail below:

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a photograph of an unmowed clump of the variety;

FIG. 2 is a photograph of a closely mowed clump of the variety;

FIG. 3 is a photograph of a tiller of the variety extracted from aclosely mowed turf;

FIG. 4 is a photograph of a clump of the variety (center) compared with`El Toro` Zoysia grass (left) and with Hawaiian `Emerald` Zoysia grass(right);

FIG. 5 is a photograph of racemes of the variety bearing inflorescensesin early, middle, and late stages of flowering; and

FIG. 6 is a photograph of racemes bearing inflorescences of the variety(center) compared with racemes bearing inflorescenses of `El Toro`Zoysia grass (left) and Hawaiian `Emerald` Zoysia grass (right).

BOTANICAL DESCRIPTION OF THE PLANT

A detailed description of the new and distinct variety of Zoysia grassplant Z-3 is:

(a) An attractive deep lusterous green color, color Green number 141 Aof The Royal Horticultural Society of London Colour Chart.

(b) The grass is low-growing, decumbent in habit.

(c) The grass spreads by stolons and rhizomes, forming a dense, uniformsurface, with an extensive root system. The stolons are a darkpurplish-red color, color Red-Purple, number 61 B of The RoyalHorticultural Society of London Colour Chart; stolons 1.5 millimeters inwidth with nodes 1.2-2 centimeters apart.

(d) Culms vary in height from 5-6.5 centimeters.

(e) Leaves rolled in bud shoot.

(f) The leaf blade is glabrous, flat, and gradually tapering to an acutepoint.

(g) The first mature leaf is 2-3 millimeters in width and 5-7centimeters long.

(h) The ligule is a very small ciliate fringe.

(g) Auricles are absent.

(h) The collar is broad, and continuous.

(i) The sheath is glabrous, except for several hairs less than 1millimeter in length at the top of the sheath at the sides of theligule; the sheath is split with separate margins.

(j) The entire plant is glaborous, except at the top of the sheath whereseveral hairs are present at the sides of the ligule.

(k) The inflorescence consists of a single spike at the top of the mainstem.

(l) The spike contains stigmas of pale yellow-green color, colorYellow-Green 150 D of The Royal Horticultural Society of London ColourChart, and anthers of dark purplish-red color, color Red-Purple 61 B ofThe Royal Horticultural Society of London Colour Chart; the glumes are2-3 millimeters long, blunt at their base, pointed at their tips.

I claim:
 1. A new and distinct variety of grass plant, Zoysia Z-3 asherein described and illustrated.